Spartan's strides to falter and flag (5,3,7)
I believe the answer is:
stars and stripes
'flag' is the definition.
(I know that Stars and Stripes is a type of flag)
'spartan's strides to falter' is the wordplay.
'to falter' is an anagram indicator (I've seen 'faltering' mean this).
'spartans'+'strides'='spartansstrides'
'spartansstrides' with letters rearranged gives 'STARS AND STRIPES'.
'and' acts as a link.
(Other definitions for stars and stripes that I've seen before include "indicators of military rank" , "indications of rank" , "The US flag" , "Standard" , "American flier" .)